April 4, 2024 Dataset Open Access

MODIS Collection 6.1 global 8-daily LAI and FAPAR

Kern, Stefan

Data curator(s)

Abstract: Original LAI and FAPAR data (see https://lpdaac.usgs.gov/products/mod15a2hv061/) are read together with their bit-encoded quality information from the HDF-files. The quality information is decoded and provided in form of separate flag layers in addition to the LAI and FAPAR data for each tile of the MODIS sinusoidal grid in netCDF file format (see https://www.cen.uni-hamburg.de/en/icdc/data/land/modis-lai-fpar.html and https://doi.org/10.25592/uhhfdm.14184). These are subsequently read and re-gridded onto an equi-rectangular climate modeling grid (CMG). Only those LAI and FAPAR values are used where i) the cloud flag indicates a maximum of two cloud influences, and where ii) cloud cover is clearly defined, i.e. "assumed clear sky" is not used. Flag layers are summarized such that there is gridded information about 1) cloud fraction, 2) fraction of average and high aerosol load, 3) primary and secondary land-cover type, and 4) primary and secondary quality flag. Primary and secondary refer to the highest and 2nd-highest pixel count of the respective type or flag within the grid cell. Note that the count of valid values differs for the grid cell mean LAI and FAPAR and their variance, and for the grid-cell mean retrieval standard deviation.

TableOfContents: Grid cell mean FAPAR; Grid cell mean LAI; FAPAR variance across grid cell; LAI variance across grid cell; Grid cell mean FAPAR retrieval standard deviation; Grid cel mean LAI retrieval standard deviation; Count of useful FAPAR or LAI values per grid cell; Count of useful FAPAR or LAI retrieval standard deviation values in grid cell; Primary quality flag; Secondary quality flag; Primary land cover; Secondary land cover; Grid cell cloud fraction; Grid cell aerosol fraction

Technical Info: dimension: 720 columns x 360 rows x unlimited; temporalExtent_startDate: 2000-02-18; temporalExtent_endDate: 2023-12-31; temporalResolution: 8-daily; spatialResolution: 0.5; spatialResolutionUnit: degrees; horizontalResolutionXdirection: 0.5; horizontalResolutionXdirectionUnit: degrees; horizontalResolutionYdirection: 0.5; horizontalResolutionYdirectionUnit: degrees; verticalResolution: none; verticalResolutionUnit: none; verticalStart: none; verticalEnd: none; instrumentName: MODerate Resolution Spectroradiometer (MODIS); instrumentType: visible_to_infrared_spectroradiometer; instrumentLocation: Earth Observation Satellite (EOS) Terra; instrumentProvider: NOAA/NASA

Methods: [1] MODIS collection 6.1 (C61) LAI/FPAR Product User Guide, https://lpdaac.usgs.gov/documents/926/MOD15_User_Guide_V61.pdf ; [2] Myneni, R. B., et al., Algorithm Theoretical Basis Document (ATBD), v4.0, http://modis.gsfc.nasa.gov/data/atbd/atbd_mod15.pdf; [3] Yang, et al., From validation to algorithm improvement. Trans. Geosci. Rem. Sens., 44, 1885-1898, 2006; [4] Morisette, et al., Validation of global moderate resolution LAI products: A framework proposed within the CEOS Land Product Validation subgroup, Trans. Geosci. Rem. Sens., 44, 1804-1817, 2006; [5] Garrigues, et al., Validation and intercomparison of global Leaf Area Index products derived from remote sensing data, J. Geophys. Res., 113, G02028, https://doi.org/10.1029/2007JG000635, 2008; [6] https://www.cen.uni-hamburg.de/en/icdc/data/land/modis-lai-fpar.html

Units: Units for all variables (see TableOfContents): percent, m²/m², percent, m⁴/m⁴, percent, m²/m², 1, 1, 1, 1, 1, 1, percent, percent

geoLocations: westBoundLongitude: -180.0 degrees East; eastBoundLongitude: 180.0 degrees East; southBoundLatitude: -90.0 degrees North; northBoundLatitude: 90.0 degrees North; geoLocationPlace: global on land

Size: (files are packed into one zip-file per year)

• 2000: 40 files, 9864980 byte / file
• 2001: 44 files (20010618 and 20010626 are missing)
• 2002: 35 files (20020101 until 20020322 are missing)
• 2003-2023: 46 files / year

Format: netCDF

DataSources:

Original data on sinusoidal grid tiles in hdf-format: https://doi.org/10.5067/MODIS/MOD15A2H.061 [last access: 2024-03-13], see also: https://lpdaac.usgs.gov/products/mod15a2hv061/ [last access: 2024-03-13]

Data on sinusoidal grid tiles in netCDF-format: https://www.cen.uni-hamburg.de/en/icdc/data/land/modis-lai-fpar.html [last access: 2024-04-04] and https://doi.org/10.25592/uhhfdm.14184 [last access: 2024-04-04]

Contact: stefan.kern (at) uni-hamburg.de

Web page: https://www.cen.uni-hamburg.de/en/icdc/data/land/modis-lai-fpar.html [last access: 2024-04-04]